Equipment

1) Main THz experiments

Custom-made setup for THz time-domain spectroscopy

Suitable for measurements of samples in steady state (solids, liquids; temperature range 10 – 900 K; application of high voltage up to 1.5 kV) and for optical pump—THz probe experiments; placed in a vacuum chamber. It can be operated in two modes:

MIRA seed: For the measurement of samples in steady state the experiment is driven with a femtosecond oscillator MIRA seed and uses a recently proposed high-brightness interdigitated semiconductor TeraSED photoswitch as the THz emitter and a 1 mm thick [110]-oriented ZnTe single crystal as an electro-optic (phase-sensitive) sensor.

Peak electric field

0.1 kV/cm

Average power

0.27 mW

Energy per pulse

3.5 pJ

Peak power

0.27 kW

Photons per pulse

~1.4×1010

SPITFIRE amplifier: For the pump-probe measurement we use femtosecond amplified laser output and the THz pulses are generated via an optical rectification (difference frequency mixing) nonlinear process in a 1 mm thick [110]-oriented ZnTe crystal. An identical ZnTe crystal is used as a sensor for the phase sensitive detection.

Peak electric field

5 kV/cm

Average power

0.7 µW

Energy per pulse

0.7 nJ

Peak power

2.3 kW

Photons per pulse

~7×1011

Fig. 1.
Photo of the setup for THz spectroscopy.

Custom-made setup for THz near-field microscopy

The experiment is driven with a femtosecond oscillator VITESSE and uses an interdigitated semiconductor TeraSED photoswitch as the THz emitter and a 1 mm thick [110]-oriented ZnTe single crystal as an electro-optic (phase-sensitive) sensor.